Zurich-based software engineer Henrico Dolfing created this very entertaining slide deck on “24 Reasons Why Twitter Sucks!” It earned first place in the Technology category of the World’s Best Presentation Contest ’09, sponsored by Slideshare.net, which ended Sept. 9. You can view all the winners in a variety of categories here.

Children’s book author and storyteller Carmen Agra Deedy defines great storytelling as “the art of letting go.” That element is pertinent to any public speaker, whether you are a keynoter, CEO leading an All Hands corporate meeting or a salesperson giving a PowerPoint presentation.

Storytelling engages an audience. In fact, in Deedy’s very funny TED Conference speech about connecting with her Cuban mother, she precedes the talk by pointing out that when Lexis wants to sell you a car, it engages you by telling a story in its commercials.

As you’ll see in this TED.com video below, Deedy is a vivid storyteller. It’s not only because she’s a talented writer, but she’s also very effective in using techniques that great speakers use to add power to their speeches, such as vocal variety and energetic body language. She doesn’t just tell the story. She relives the story by breaking into character dialogue.

Comedian and playwright Julia Sweeney performed a hilarious excerpt from her one-woman play, “Letting Go of God,” at the 2006 TED Conference. The video of the speech has recently been made available as part of a partnership between TED and Google Video.

Sweeney’s speech is a great example of how a speaker can make a story come alive by executing strong vocal variety, vivid facial expressions, hand gestures and dramatic pauses. Of course, what would you expect from a former cast member of Saturday Night Live?